Obesity is defined as the excess accumulation of body fat to an extent that is harmful to health (Edited by Per BjInternational Textbook of Obesity. West Sussex: John Wiley & Sons. Ltd., 2001, ISBN 0-471-98870-7, 3-22.). Obesity was considered a symbol of wealth in the past. Today, however, excess body weight has been proven to be a risk factor for various pathological conditions, such as diabetes and arteriosclerosis, leading to increased morbidity and mortality and causing social and psychological problems. Thus, obesity is now regarded as a chronic disease that should be treated (Manson J E, Willet W C, Stampfer M J, Colditz G A, Hunter D J, Hankinson S E, Hennekens C H, Speizer F E. Body weight and mortality among women. N Eng J Med 1995, 333:677-685; Hubert H B, Feinleib M, McNamara P M, Castelli W P. Obesity as an independent risk factor for cardiovascular disease: a 26-year follow-up of participants in the Framingham Heart Study. Circulation 1983, 67:968-977; Pi-Sunyer FX. Medical hazard of obesity. Ann Intern Med 1993, 119:655-660; Huang Z, Willett W C, Manson J E, Rosner B, Stampfer M J, Speizer F E, Colditz G A. Body weight, weight change, and risk for hypertension in women. Ann Intern Med 1998, 128:81-88; Colditz G A, Willett W C, Stampfer M J, Manson J E, Hennekens C H, Arky R A, Speizer F E. Weight as a risk factor for clinical diabetes in women. Am J Epidemiol 1990, 132:501-513).
According to the World Health Organization (WHO), more than 1.2 billion people worldwide are classified as being overweight or obese. In 2000, about 65% of adult Americans were estimated to be overweight (World Health Organization, Obesity: Preventing and Managing the Global Epidemic Report of a WHO Consultation on Obesity, 1997 Jun: 32-5; Flegal K M, Carroll M D, Ogden C L, Johnson C L, Prevalence and trends in obesity among US adults, 1999-2000 JAMA 2002, 288:1723-1727). Also, about 300,000 deaths per year are associated with obesity in the US (Allison D B, Fontaine K R, Manson J E, Stevens J, VanItallie T B, Annual Deaths Attributable to Obesity in the United States, JAMA 1999, 282:1530-1538).
Excess weight or obesity contributes significantly to numerous diseases. Around the world, about 80% of diabetes cases and 21% of cardiovascular disease are attributable to excess weight. As well, weight is associated both directly and indirectly with various types of cancer, including cancer of the uterus, kidneys and breasts. People who are overweight or obese have a greater likelihood of developing sleep apnea, osteoarthritis, cholelithiasis, and others (Stein C J, Colditz G A, The epidemic of obesity, J Clin Endocrinol Metab 2004, 89:2522-2525; Kopelman P G, Obesity as a medical problem, Nature 2000 Apr. 6, 404(6778):635-43). As described above, obesity reduces life expectancy and threatens health.
Obesity imposes a large economic burden on societies. Americans gained an average weight of about 10 pounds (4.5 kg) during the 1990s. Airlines spent $275 million to burn 350 million more gallons of fuel in 2000 to carry the extra weight (Dannenberg A L, Burton D C, Jackson R J, Economic and environmental costs of obesity: the impact on airlines, AM J Prev Med, 2004 Oct. 27(3): 264). The direct and indirect health care costs associated with obesity have been estimated to amount to about $117 billion in the US every year. In South Korea, according to data from the 2001 National Health & Nutrition Survey, the social and economic costs of obesity account for 1001.7 billion Won. This, which is the sum of medical care costs of obesity and the value of lost and reduced productivity resulting from premature death and illness, accounts for about 5% of total national medical care expenditures (the 2001 Korean National Health & Nutrition Survey conducted by the Korea Institute for Health and Social Affairs under the Ministry of Health and Welfare). In 2000, the global market for obesity drugs was estimated at about $1.3 billion in 2000. This market is expected to reach $8 billion in 2010.
Obesity is seldom curable because it is caused not by one factor but by a complex interplay of several hereditary, environmental, social and psychological factors. Obesity occurs when energy intake exceeds energy expenditure. Thus, obesity arising from energy imbalance can be resolved by reducing caloric intake and increasing caloric expenditure. At present, there are two major options for obesity treatment: one is to make lifestyle changes through dietary therapy, physical activity, behavior therapy, and the like, and the other includes drug therapy and surgery.
Patients should definitely make efforts to change their lifestyle before starting drug treatment or having weight loss surgery. However, is not easy to change one's lifestyle, and moreover, merely making a lifestyle change without using drugs is of limited effectiveness for losing weight. Thus, in many cases, weight loss can be achieved more effectively by making lifestyle changes along with drug therapy.
At present, sibutramine and orlistat are the only medications that have been approved by the US Food & Drug Administration (FDA) for use in the treatment of obesity. Sibutramine (Reductil®) is a serotonin-norepinephrine reuptake inhibitor, and orlistat (Xenical®) inhibits gastric and pancreatic lipases (Yanovski S Z, Yanovski J A, Obesity, N Engl J Med 2002, 346:591-602).
However, the two obesity medications have not been widely used due to some limitations. Common side effects of sibutramine include increased blood pressure, insomnia, dry mouth and dizziness. People having cardiovascular diseases or poorly controlled high blood pressure should not take sibutramine (H S Park, Sibutramine, The Korean Journal of Obesity 1998, 7(4):270-3).
Orlistat also has limitations in use for obesity treatment. Common side effects of orlistat include diarrhea, oily stools and fecal incontinence. As well, orlistat has not shown great therapeutic effects in people, like Koreans, having a low fat diet compared to Westerners (S M Kim, Study on Orlistat, The Korean Journal of Obesity 1998, 7(4): 287-92). The two obesity medications need to be studied with an eye to their long-term safety.
Due to the drawbacks of conventional medications developed for obesity treatment, there is an urgent need for the development of a medication that is highly effective for losing weight and has few side effects because it has a novel action mechanism. In this regard, the inventors of this application assumed that Chinese herbal medicines have potential as an alternative to conventional medications for obesity, and have conducted intensive and thorough research to evaluate their effectiveness, resulting in the finding that a composition comprising Herba Ephedrae and Thallus Laminariae seu Eckloniae or comprising Herba Ephedrae, Thallus Laminariae seu Eckloniae and Radix et Rhizoma Rhei has an effect of suppressing an increase in body weight, leading to the present invention.